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731.
Abstract

With the income increase of elderly people in Beijing and the improvement of leisure facilities since 2000, the quality of elderly people leisure life in Beijing has obviously increased compared to ten years ago. According to the investigation and comparative analysis on more than 900 elderly people, who usually exercise in public parks in Beijing City, we have found out several new features of elderly people’s outdoor recreation in Beijing: the increase of the leisure time, the expansion of leisure space, the individuation of interest and the diversification of consumption. The leisure life quality evaluation index system of urban elderly people can be built based on these analyses. In order to accommodate the development tendency of elderly people’s demand for leisure diversification, we should strengthen the organization and management of elderly people’s leisure activity in urban construction, and pay more attention to function complementation between communities and parks.  相似文献   
732.
为研究新型无氨泡沫凝胶的胶凝特性和灭火特点,采用倾斜试管法分别测试了不同反应物浓度、温度、pH值和发泡剂浓度等参数对新型泡沫凝胶成胶时间的影响,同时通过灭火实验对泡沫凝胶的消防特性进行了研究。结果显示:当水玻璃与促凝剂的质量比在1.33—4.0时材料成胶时间满足煤矿灭火要求;pH值在6.9—8.5时成胶最快;成胶时间随温度升高而减小;发泡剂浓度对成胶时间影响不大;泡沫凝胶灭火效果良好且有效延长了复燃周期。因此泡沫凝胶在矿井消防中有很强的实用价值,并且可通过限制反应物浓度、pH值、温度等参数,更高效的控制成胶时间。  相似文献   
733.
Computers are used in the outdoors and in connection with cold store work. Cold hand and fingers limit data input, as studied here. Six input devices; trackballs, pens, and a mouse were tested by 19 participants in a Fitts’ target acquisition task with 2 target sizes under 2 experimental conditions; warm and cold right hand. Measures were acquisition times, number of errors, participant’s preferences, and observed handling of the devices. Effects of device, target size, and cold were significant. Learning and attempts to improve handgrip were confirmed. Large enough targets, a thick pen, and a mouse make computer work practicable in the cold. Direct visual feedback, as with pen on template with target images, shortened acquisition times by half a second.  相似文献   
734.
Gloves afford hand protection by minimizing skin contact. The effectiveness of medical gloves to protect against permeation of the monomers, methyl methacrylate (MMA), ethylene glycol dimethacrylate (EGDMA), and 1,4-butanediol dimethacrylate (1,4-BDMA), was assessed focusing on permeation rates and degradation of glove materials caused by monomer contact. Fifteen different brands of gloves were tested using a European Standard procedure. Surface images of glove materials before and after exposure to the monomer mixture were obtained using a scanning electron microscope. The standard is not applicable as the only method for estimating the safety of gloves, but it is useful as guideline together with the cumulative permeation of acrylic monomers. Monomer contact on the outside resulted in substantial swelling of most glove materials, and structure changes of the inside surface.  相似文献   
735.
本文通过对KZ1床层、KZ2床层、KZ1和KZ2复合床层在不同床层厚度条件下,对氯化氰蒸气的动活性进行对比试验,并对试验结果进行分析,得出了后者并非前两者之和,而有了大幅提高的结论。  相似文献   
736.
Water‐level trends spanning 20, 30, 40, and 50 years were tested using month‐end groundwater levels in 26, 12, 10, and 3 wells in northern New England (Maine, New Hampshire, and Vermont), respectively. Groundwater levels for 77 wells were used in interannual correlations with meteorological and hydrologic variables related to groundwater. Trends in the contemporary groundwater record (20 and 30 years) indicate increases (rises) or no substantial change in groundwater levels in all months for most wells throughout northern New England. The highest percentage of increasing 20‐year trends was in February through March, May through August, and October through November. Forty‐year trend results were mixed, whereas 50‐year trends indicated increasing groundwater levels. Whereas most monthly groundwater levels correlate strongly with the previous month's level, monthly levels also correlate strongly with monthly streamflows in the same month; correlations of levels with monthly precipitation are less frequent and weaker than those with streamflow. Groundwater levels in May through August correlate strongly with annual (water year) streamflow. Correlations of groundwater levels with streamflow data and the relative richness of 50‐ to 100‐year historical streamflow data suggest useful proxies for quantifying historical groundwater levels in light of the relatively short and fragmented groundwater data records presently available.  相似文献   
737.
This article aims to explore people's connections to or disconnections from the future and the implications of this for their perspectives on equity, justice and ethical issues related to energy consumption. Everything people do is embedded and extended in time across the modalities of past, present and future, making time an inescapable aspect of our existence, yet one that often remains invisible and intangible. Debates about energy and environmental equity have raised questions about the extent to which people today should bear responsibility for the consequences of their behaviour for future generations. Seemingly intractable difficulties have been identified, however, in people's abilities to connect their present actions with their potential future consequences and thus take on such responsibilities. Drawing on data from interviews about energy consumption practices, this article explores whether people's living temporal extensions through younger generations of their families influence their views and practices around energy use in both the present and anticipated future. Through exploring these issues we offer a contribution to the ethical debate around responsibility for future generations.  相似文献   
738.
为解决铁路综合客运枢纽客流疏解预警忽略旅客心理感知与焦虑问题,基于状态焦虑问卷,定量描述旅客焦虑状态,通过引入心理测量学中积极率划分客流疏解等级阈值,确定枢纽客流疏解预警等级,构建以旅客感知疏解时间为预警指标的回归预测模型。研究结果表明:模型可定量预测枢纽站各种交通接驳方式客流的感知疏解时间,准确描述枢纽站预警等级,研究结果可为管理人员选择相应疏解措施提供依据。  相似文献   
739.
以运行费用作为膜生物反应器(MBR)运行经济性的考核指标,建立了MBR运行费用的计算模型,重点考察了膜通量、曝气强度、抽停时间、混合液悬浮固体质量浓度等操作条件对MBR运行经济性的影响.结果表明,膜通量在临界值5 L/(m2·h)时运行费用处于最低值;曝气强度过高或过低都会使系统运行费用增加,而经济曝气强度(气水比)为30:1;当抽吸时间≤12 min、停抽时间≥3 min时,运行费用变化缓慢,但抽吸时间或停抽时间超过临界值后,运行费用迅速上升;混合液悬浮固体质量浓度高于5.0 g/L时,运行费用随混合液悬浮固体质量浓度增加迅速递增.工程运行表明,运行费用模型预测值与实际值具有较好的一致性.  相似文献   
740.
A novel inverse technique is proposed to quantitatively characterize macroscopic variability in aquifer reactivity in a Lagrangian representation. Reactivity heterogeneity is expressed in terms of distributions of flux over cumulative time of exposure of the solution to reactive surface area, termed here 'cumulative reactivity'. In cases involving single aqueous species the combined effects of physical and reactivity heterogeneity on reactive solute transport can often be established and further investigated through joint distributions of flux over travel time and cumulative reactivity. The inverse technique requires the breakthrough curve of a passive tracer to determine the distribution of flux over travel time, and additional breakthrough curves of reactive tracers provide additional moments of the distribution of flux over cumulative reactivity given travel time. Thus breakthroughs of one passive and two reactive tracers can provide the mean and variance of the distribution of flux over cumulative reactivity. This Lagrangian characterization is achieved with knowledge of the types of reactive surfaces present, but not their spatial locations. The distributions can subsequently be applied via forward modeling using the same technique to predict breakthrough curves of other solutes undergoing first-order reactions in similar physically and chemically heterogeneous configurations.  相似文献   
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